Pentachlorophenol

Structural formula

• Numbering system
• Physical property data
• Toxicological data
• Ecological data
• Molecular structure data
• Computing chemical data
• More
  • Properties and Stability
  • Storage method
  • Synthesis method
  • Purpose

Numbering system

CAS number:87-86-5

MDL number:MFCD00002162

EINECS number:201-778-6

RTECS number:SM6300000

BRN number:1285380

PubChem number:24898341

Physical property data

1. Properties: White needle-like crystals. It has a strong pungent smell when hot.

2. Density (g/mL, 22℃): 1.978

3. Relative density (20℃, 4℃): 1.978²²

4. Melting point (ºC): 190

5. Boiling point (ºC, 10.5KPa): 310℃ (decomposition)

6. Crystal phase standard claims heat ( Enthalpy) (kJ·mol^-1): -292.9

7. The gas phase standard claims heat (enthalpy) (kJ·mol^-1): -225.1

8. Gas phase standard entropy (J·mol^-1·K^-1): 447.84

9. Gas phase standard free energy of formation (kJ·mol^-1): -132.0

10. Gas phase standard hot melt (J·mol^-1·K ^-1): 190.29

11. Vapor pressure (kPa, 25ºC): Not determined

12. Saturated vapor pressure (kPa, 60ºC): Not determined Determined

13. Heat of combustion (KJ/mol): Undetermined

14. Critical temperature (ºC): Undetermined

15. Critical pressure (KPa ): Undetermined

16. Log value of oil-water (octanol/water) partition coefficient: Undetermined

17. Explosion upper limit (%, V/V): Undetermined

18. Lower explosion limit (%, V/V): Undetermined

19. Solubility: Easily soluble in ethanol and ether, soluble in benzene, slightly soluble in cold petroleum ether , almost insoluble in water.

Toxicological data

1. Toxicity classification: highly toxic

2. Acute toxicity: Oral administration – rat LD50: 27 mg/kg; Oral administration – mouse LD50: 36 mg/kg.

3. Irritation data: skin – rabbit 10 mg/24 hours, moderate; eyes – rabbit 0.1 ml/24 hours, mild.

4. Inhalation or skin absorption of this product can cause headache, fatigue, irritation of the eyes, mucous membranes and skin, neuralgia, hyperhidrosis, dyspnea, cyanosis, liver and kidney damage, etc.

Ecological data

It is highly toxic to fish, and the lethal concentration of fish and shrimpLD50 is 0.3~0.6mg/L. The maximum allowable concentration of harmful substances in the air of China’s workshops is 0.3mg/m3. This product is irritating to eyes and respiratory tract.

Molecular structure data

1. Molar refractive index: 52.60

2. Molar volume (cm³/mol): 147.6

3. Isotonic specific volume (90.2K ): 401.6

4. Surface tension (dyne/cm): 54.7

5. Polarizability (10^-24cm³): 20.85

Compute chemical data

1. Reference value for hydrophobic parameter calculation (XlogP): None

2. Number of hydrogen bond donors: 1

3. Number of hydrogen bond acceptors: 1

4. Number of rotatable chemical bonds: 0

5. Number of tautomers: 2

6. Topological molecule polar surface area 20.2

7. Number of heavy atoms: 12

8. Surface charge: 0

9. Complexity: 150

10. Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 0

13. Determine the number of chemical bond stereocenters: 0

14. Number of uncertain chemical bond stereocenters: 0

15. Number of covalent bond units: 1

Properties and stability

1. White powder or needle crystal.
Soluble in dilute alkali solution, ethanol, acetone, ether, benzene, etc., slightly soluble in hydrocarbons, almost insoluble in water. It reacts with sodium hydroxide to produce white crystalline sodium pentachlorophenate.
This product is moderately toxic. When the concentration in the air exceeds the standard, wear a gas mask. Operators should wear safety masks, appropriate protective clothing and chemical-resistant gloves.
2. Toxic. The oral LD50 of male rats and female rats are 146mg/kg and 175mg/kg respectively. Irritating to skin. The production site should be well ventilated and operators should wear protective equipment.
　

Storage method

This product should be sealed and stored in a cool, dark place.

Packaged in plastic woven bags lined with plastic bags, net weight of each bag is 50kg or 100kg. Pay attention to fire and moisture protection during storage and transportation.

Synthesis method

1. Add solid sodium hydroxide to the stirring tank, add water while stirring to prepare a solution of about 160g/L, and then stir the molar ratio of hexachlorobenzene to sodium hydroxide to 1: (2.5~2.6) According to the proportion, add hexachlorobenzene to the alkali solution, stir evenly and pump it into the high-pressure hydrolysis kettle. Stir and heat up until the pressure in the kettle reaches 2.0MPa. Stop heating. Due to the exothermic reaction, the temperature in the reaction kettle will automatically rise to 230°C and the pressure in the kettle will reach 2.55MPa. Keep the reaction at 230°C for 20 minutes, and the hydrolysis will be completed. Then the pressure is released, the material is cooled and crystallized, and filtered to obtain scaly solid sodium pentachlorophenate.

2. Add sodium pentachlorophenol to the reaction kettle , add 31% hydrochloric acid under stirring to acidify, and keep the acidification temperature at 80~90°C. After the acidification is completed, the product is washed with water, filtered and dried to obtain the product.

3.Chlorination is carried out by passing chlorine through trichlorobenzene to obtain hexachlorobenzene. Hexachlorobenzene and a caustic soda solution of a certain concentration are heated and hydrolyzed at a certain temperature and pressure. The reaction product is cooled, crystallized, Filter and dry to obtain sodium pentachlorophenate.

Purpose

1. Organic synthesis. Pesticide residue analysis standards. Insecticides to control termites. herbicide. Wood preservative. It is used for organic synthesis, barnyard grass control in rice fields and wood preservation. It is also a widely used antifungal agent with high sterilization effect. It is suitable for plastics such as polyvinyl chloride, coatings, leather, adhesives, rubber, fibers, paper, etc. The general dosage is 0.1-0.5%. It is also effective in controlling termites, snails, etc.

2. Bactericides, used in combination with certain anionic surfactants, can significantly reduce their dosage and improve the bactericidal effect. But it should not be used together with cationic agents (such as quaternary ammonium salts, etc.). The mass concentration of sodium pentachlorophenate is generally 50mg/L.

3. It is the cheapest and widely used antibacterial agent, and it is also effective in killing termites, borers, etc. Commonly used as antifungal agent for wood, fiber products, starch adhesives and leather. However, it is not suitable to be used in cables or wires of electrical equipment because its volatile matter or chloride-containing compounds generated by decomposition will corrode the equipment. It is also a seed dressing agent and soil fungicide, used to prevent and control cotton blight and damping-off, wheat and sorghum smut, potato scab, etc.